Most educational. In the UK if the tank is used for SCUBA it must be (like yourselves) tested every 5 years but the regulator has to be tested every two years. Even if the tank is used for an airgun, the bottle has to be 5 year tested and no shop will fill it if is not stamped with the current validity from and to dates. Carbon fibre bottles are deemed unusable after 10 years whether they pass the HS test or not.
What about making a video to show us around your workshop and your workbench please? It will be most interesting to see how your organize your tools, workbench and workflow around the bench. Thank you for your efforts in educating the diving community.
You might want to invest in a Inspection Scope for Cylinder Neck Internal Thread Examination, it's impossible to see microscopic hairline cracks in the threads without it.... it's almost like guessing when you use a mirror.
You are correct, hairline cracks are easy to overlook. I do have 3 additional viewers other than a mirror. Optiviewer, Optical Plus scope and Visual Plus 3 (eddy current machine). When I teach VIP Inspectors and Hydro Testers to locate necks cracks I show them how to use all 3. Currently I have 6 tanks with confirmed neck cracks so my students can practice. I remember when these cracks first started to develop in the 80's we would spot them because they were leaking during fill, by 1989 Luxfer ceased the use 6351 aluminum the culprit of the SLC. We come a long way since. Soon I'll be posting more videos, just in the middle of summer madness with little spare time. Thanks for watching.
well, now i know how the neck of my tank got cracked, im thinking all this testing is just doing more harm than good. its like, do you change your oil and then drive like its a racecar
Yeah, I was literally just watching and was thinking the same thing. I went to the comments to see if anyone else was wondering how hard it is on these tanks, just to have it tested. I am trying to research tanks for paintball and pcp air rifles. I know the carbon fiber paint ball tanks are given a life span of 15 years, but I feel like getting them tested every 5 years is harder on them than just being careful with how you use them. And all the things I read on forums say they have never heard of a carbon tank failure in the field. Maybe a cheap regulator failure but never a tank. I read about a place purposely gouging a tank 50% through the side and filling it to 13,000 psi before it failed . But I don't think they are even catastrophic failures. I think it's more of a slow leak, and maybe the fibers start to unravel. I just think if you take care of them and not have them filled by amateurs that dont filter the water out or fill them up fast, they shouldn't have a catastrophic failure. No one will ever admit it, though.
What is the total cost of the equipment needed to conduct the hydrostatic test and what are the certifications needed to conduct those test? Thank you.
Did a TON of these in the mid 80's ..our shop serviced a lot of shops in Palm Beach County .. The lid I had needed to be screwed down ..didn't have those quick release's you have ... I used a pipette scale to read the expansion ..scary sometimes when the pressure is nearing it highest point ...never had one give way thou ..we didn't have the stamp most have ..I had to stamp all 4 of them B3-83 I think (long time ago) ..our drying system was a tank rack with pvc plumbing we used a vacuum cleaner to blow the air and put it outside so the suns heat would help ...This is where I began my Scuba Carer ..coming from being an Auto/Truck Mechanic ... Memories ..Good Video ..I like the scale better than the pipette ....
Yes I started with Burette tubes to read water expansion, the scale is much better. They also have a pneumatic closure for lids now, it's about 3,000 bucks, one day I 'll break down and buy it.
Thanks for the informative video. I am here trying get a better understanding how all this works. Also I'm dabbling in a different application,. PCP for air rifles. Just purchased a carbon fiber over Aluminum tank. I have my own compressor and Have had an old retired tank laying around still holding air(Scott scba) But I will not add pressure to it at this point until I have it hydro'd (if it can be be done) The tank exterior is fine visually and I know that's as far as it goes. Reason I'm here again is Safety,. not sure if it matters, my tanks stay indoors and are not banged around. The whole 15 year thing... I'm trying to grasp,. I've seen tanks 40 yrs old holding pressure, Now that being said they could be a grenade with the pin pulled or they could last longer than I'm around(I Don't know)That's why I'm searching this information and not Just here. I'm not fond of the idea of having a hole drilled in my tank (Just Because Of A Date)and no test actually performed to justify. And I may be wrong in my thinking, and if I find that out I will change my thoughts on this. Closing thoughts: I know folks way smarter than me designed this format/platform. The other 2(TWO) factors is Safety And MONEY,. and that's what I am trying to separate if that's even possible. Now this new tank I'm getting, I will be installing the Valve and will be regularly inspecting the interior and will know how this tanks full history will be. The Scott SCBA tank I have went into burning buildings and sure it had some abuse including drops and being banged around. And again I have it Idle at this point. But it's a bit of history to me. Thank you again.
SCBA bottles are made from thin aluminum shell wrapped with carbon fiber and resin finish for strength. The lifespan of 15 years is designated by the manufacture, they believe after 15 years these bottles can weaken and no longer be trustworthy to hold pressure. These bottles easily damage, any exposed fibers is considered a weak stop. Thanks for watching... be safe.
Very good video, would like to have this in Sierra Leone to test my 25 tanks, Faber and Luxfer, plus we have 50 L volume for Surface supply, we are a danish Commercial diving company in west Africa, no tests available, I do Visuals, will now buy more test equipment and get a Water Jacket and the rest to pressurise the waterfilled tank.
I knew there was an elastic allowance but didn't know about the permanent one. Given that each test permanently expands the tank a little is there consideration of how many times the tank has been tested? Ie does a tank that's been tested 10 times have the same permitted level of permanent expansion as a new tank?
@@scubatechkeylargo Does the amount of permanent expansion each test taper off over time or is it constant. If constant that would seem to make the test somewhat destructive in the long term.
With each test the permanent expansion is for the day of testing, it is not accumulative. The permanent percentage isn't added to each subsequent test. The tanks do relax if left in the well overnight you can see the permanet reading shrink. No harm in the long term.
Over pressurizing is not a good practice regardless of steel or aluminum, it can lead to metal fatigue. All tanks are elastic and will flex while filling, hydro testing is designed to catch metal fatigued/ weaken tanks before a catastrophic failure. I do believe over pressuring tanks can shorten its lifespan by causing metal fatigue. Thanks for watching!
I think in the United kingdom scuba tanks can only have a 3 year test,, I have a 300 bar tank that I use for refilling filling my air rifle,, removable air tank up with compressed air,, but my 300 bar scuba tank has to be marked with a prominent sticker saying,, ""for serifs use only"",, and it can then stay in test for 5 years,, but the stupid part is,, the 500cc x 300 bar air bottle that screws to my air rifle,, never need to be retested!,, maybe highly compressed air hand grenades,, dont count as being dangers!,, but the sure go with one hell of a bang,, if you shoot one with a 308 Winchester rifle,, now I can see were the film makes got the idea of using a compressed air scuba bottle,, to blow up JAW'S,, because it work's!
That's good to know about tanks in the UK, I'm not totally familiar with regulations in the UK. Compressed air tanks are safe unless put under unintended use, such as a 308 round. LOL Thanks for the comment.
DOT in the US believes every 5 years is good, our tanks are 3000 to 3500 psi at max working pressure. The tanks in the UK may be at higher working pressure, therefore 3 year hydros might be cautious.
How does this work with a let’s say a FABER hot galvanized steel with SP13488 specification? Is it tested the same way or do all galvanized cylinders done differently and only look at the REE as being pass fail?
Faber Hot dip gal. tanks are now coming into their first hydro testing. As of the current date Faber has not published any special testing procedures other than the 10% rule. I suspect as testers fail these tanks Faber will petition DOT just like ( Worthington & PST) for special testing using REE and multiple pretest. Galvanized cylinders have a false fail on first and sometimes second test, this is why special procedures must be applied. I've made several inquiries about this issue with Faber Galvanized tanks, so far nothing.
Faber Hot dip gal. tanks are now coming into their first hydro testing. As of the current date Faber has not published any special testing procedures other than the 10% rule. I suspect as testers fail these tanks Faber will petition DOT just like ( Worthington & PST) for special testing using REE and multiple pretest. Galvanized cylinders have a false fail on first and sometimes second test, this is why special procedures must be applied. I've made several inquiries about this issue with Faber Galvanized tanks, so far nothing.
Tank valves are torqued to 60 ft. lbs. , however the hydro adaptor doesn't require torque. A leak will be easily detectable when pressurizing the cylinder, mainly because the machine won't build pressure.
Can you do an identical video with a LP steel tank showing the REE and the Plus stamp? It seems to be a mystery to many dive shops still. Thanks. Donate for a Dream
Yes, I have in mind to show steel hydro test. PST & Worthington tanks require multiple test versus single test on aluminum. July is busy with lobster season around the corner, but I will put a video together as soon as possible.
The test results don't give life expectancy, however the percentage of expansion can give a clue as to the metal fatigue. For example a typical result for normal used tanks is anywhere from less than 1 % to 4 or 5 %. when approaching 8% to 9% is plausible conclude the tanks has had heavy use, 10% is a fail.
I only test scuba tanks, 3AL, 3AA, 3A and Special Permit tanks. SCBA tanks are commonly used by fire fighters, paint ball & air riffles. The testing procedure is basically the same except for the stamping. SCBA are not stamped, they adhere a dated label with resin.
Tanks have different test pressures general rule is 5/3 of working pressure, for example 3000psi, test pressure is 5000psi 2400 psi, test pressure is 4000 psi 3442 psi, test pressure is 5250 psi
@@scubatechkeylargo so if it’s at 5000 psi. Is there a range you are allowed to go up to? For example 5200? This is interesting and thank you for replying
5000 is the actual test pressure, the only reason to go above is for re-test due to some mishap during the test. The re-test is 10% more which would be 5500 psi.
